01 -
Bring a large pot of water to a boil and cook sweet potato chunks until very tender, approximately 15 to 20 minutes. Drain thoroughly and transfer to a mixing bowl to cool slightly.
02 -
Using a mixer or potato masher, combine sweet potatoes with melted butter, brown sugar, heavy cream, beaten eggs, vanilla extract, cinnamon, nutmeg, and salt. Mix until silky smooth and uniformly creamy.
03 -
Pour the sweet potato mixture into a greased casserole dish and spread evenly. Bake in a preheated oven at 350°F for 25 to 30 minutes, or until set and slightly bubbly at the edges.
04 -
Remove the casserole from the oven and evenly scatter mini marshmallows across the surface, covering completely.
05 -
Switch the oven to broil and return the dish for 1 to 2 minutes, watching closely until marshmallows are golden and toasted. Serve warm immediately.